[PATCH 0/1] MR8673: win32u: Also flush the GL drawable if the client surface is offscreen.

[Rémi Bernon (＠rbernon)]

Making sure the driver will present the surface for games drawing to the
front buffer.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=58515
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=58534